A conventional mobile communication device (e.g., a mobile phone) includes a housing and a display screen fastened to the housing. The display screen is now occupying a higher and higher surface area on a front surface of the conventional mobile communication device, and the housing is now occupying a lower and lower surface area in the front surface of the conventional mobile communication device, so that an optical package structure in the conventional mobile communication device is difficult to be arranged at a position corresponding to the housing. For example, in the conventional mobile communication device that has the display screen occupying at least 80% of the front surface, the display screen needs to be formed with a hole in a corner thereof for facilitating the arrangement of the optical package structure. Accordingly, one of the topics in the related art is how to improve on the arrangement of the conventional optical package structure at a position corresponding to the housing.